SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1463f214985f071059b2fbc3c0a8238f96b8ac63e01a905088704a15f697193f' 
  AND token = 'kpU2r3muF3eG+xI1g+tOXwXk/7Xk5Zd/53FTZVI+nvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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