SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd598f2cb11b2b14daa1a9d0dab35fa3fe44d402157b2c8023db9c25920591884' 
  AND token = 'sFzXKoUEItWGybjBpelkiZCzElE/Rt8uGnUSXO4f/BQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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