SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd5c63868e81cf5baee0523aebaba742c219182a0320ffd6080448453a94cf1c' 
  AND token = 'BGWb7hF+ITJhzlt6ZF0PZ+5pOSw9+m4aBa/NbuKwX9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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