SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8bda942432f11c09ca5ab84bb725f4f8fb920b411fc89e46449650ac49cfcbe' 
  AND token = 'c4w5sGNSFTYoBW5XcCkMAsUz3rSaNnmpm+VUcrdfiP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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