SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '758e32ce0ed502e6ff6dbb9f8223db60dd8391fa4caaa4d45f8b13ab819cb476' 
  AND token = 'vjwsleWTPuIWKhChohueMHxoF0wk6yKcWZqdWA5q2w4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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