SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cb1bb91df4cb9555d1ca7c55389ab182ad4225e64be01194f3990b8f099e164' 
  AND token = 'itW41Ystt5nHTyd/p/mhpJV/L6icE/pp+6Jj7qQQaW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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