SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4d4d5761172d93ff32b90298850259faf5c84df1217a1fced0ae547492ea5276' 
  AND token = '6hRL/qY3KHv4205DFx9YkzaaXRZ5ZR0N2Xo9JRB9DG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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