SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '277fca27ee5154cc6d5ba4b86fd131c1ce5294626bab341c551282c064760c53' 
  AND token = 'VO+9b9Dhd0UOtZylwwZa+14F3wAHQVbk1gMtHlf/+jU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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