SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fe16884b7657cb2567c209d93ee59c71d73d64f2b7ef1a6faad24413ccf06b0' 
  AND token = 'eEVLMAYvpN8ad1HPxTuCcz0jtcaohCgrrpQDb1Qk6AY=' 
  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"
    }
  }
}