SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4315244528c99e01b85767ad2f9b8d5305ade5161f4a2a2facdc26a7705deac7' 
  AND token = '+9sp/OJhLdJISiHbZcs493DqC3FAMuo22NZuy8gYKwk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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