SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ecafa7a9c9a160971ced81abb27c48fe007d11da3fca3ebc61a7a2cadc25319' 
  AND token = 'y/ovmoCttANwkTXkp6J9mKHpP4RaykasmdWk/GyNGZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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