SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fa25b5ca18b3664dec88ad57511d798b5ea6e9665c24b0494b892d17823ad29' 
  AND token = '7cWzR/RwwWX/jcr2c38HwEjO3t1DgoJYX1ozCGYVttY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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