SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b2f1e3a53a122e5df04fd324c7ef405e4064404ec410997aadf77116841fe02' 
  AND token = 'O9daj00vTArUz4PvoCPLx820VMbT7V0CYoVdjKT2EbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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