SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4a5108cf7a4b502e7b0963a4532df62ba0bee2062817ebb21fe57e1b51c125d' 
  AND token = 'mPiyPYqfcCOZnpDwW8jinqYNxr4bygwmnvE/oJX1clg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}