SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59eb4932fc70908c8951e5c157328907b92d8731bf874f38542e5ca8fd80d913' 
  AND token = '+Rtx4wHpqrLBG8Ubu7pzD1RLkPGxkfYPg1UVs+iPJPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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