SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8157b5a600b053362198edf18b9339d759acaedc90b7694e6a7ebc6cf21b8f5' 
  AND token = '56Zp8lKg+xf9SMvwo/vU5jeYGF2rsPuOh8BkcjD1KHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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