SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a9753480847fd66aeba3111fe11783c136b62759741c7a60cdeaf0104a67648' 
  AND token = 'JzHyBvTB/Zgakx1wKQhlq5KzI5iLNH3soDMnv9+l0eQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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