SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c59045cd6410219b51a32cdc03a0a3ab0a824daff91e5c465edbaa4a41b989fb' 
  AND token = 'w1iM/DcGnUUdJ01kajrqnop4PRdforHHvBBTT1vRZGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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