SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '000bc088d83f3cc610aa1b542366e3b183ac396fbf4bfda3e3e1db9797250030' 
  AND token = 'cFYxLXYYAVzOIsOXDR3nddaGghw2Scb+Oxm+StbJgbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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