SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3cce054ab6a8491d922c4308a86806f983af345266c38411c6808c4873dde081' 
  AND token = 'NhpSL6DqvUboanc8Vut3PP+5O0c5TiQDnFqK4eWf+Rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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