SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24b3b994e1df8de2af87e61b82fb2c1d78adba37e77ab955e19b337bf969a37b' 
  AND token = 'gKjAu/u0tAsQzGDtnGT85JaTPlGYYIo6XWd6Ls8B5ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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