SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b95195827780343336d5d023925dee2626260f238c5f0d70795c34415e719787' 
  AND token = 'lUVHWaabV1LefT3DQYzKlYAWusvM+grltwm1N/S/NS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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