SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0538ecbf9111c2e45f2814d7ed3f07a6f74741bddc286dc68e818d748e36fd67' 
  AND token = '0GaLpspJmbsLOtfIC6kJ+S3C5si7/w2MSDLcUHr1/LY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}