SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37ce053dd0cb633c3306e27ee899802b969e5dbd3f1b1b2984ae4caf59fa9a65' 
  AND token = '2PTHzFdyVjguOtOcTVZEPOWfvOA4PfWEHXAmMh4L+Rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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