SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a48cca995d6a664084f2478bfdb0da0ece6b1397114645573a3aaf3063539168' 
  AND token = 'w9UphbkhIcjH23/iiWfBqij+0ClZByPx+xHRTpvxmaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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