SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87383497e6d7b9187703e3f84040f656bef01d6a54d52d3c4e056071fe922d43' 
  AND token = 'JreR2ZQiIxkQ49bmY8zv+IPLBPBfBzSLupUFOyp5dXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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