SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c10081f98775ecb98042e268210260f90e9a3bb8bce953e0042510f04954584b' 
  AND token = 'IULTPNeJxiR0QrZOyUfBGAM+o7nf81+XzPIIwM1CNpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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