SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42e8ea1f614ff9da434919465cef0c5bbc8cdbaae6b82c4b26888b46e5fdd01c' 
  AND token = 'ouDnObR+VM8a8TPEyAzW6kx39miMlA6T7iGSaILF57M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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