SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd75c9a0b699179aba7dbed150a1069dc1925cfd3f924a0be7fa85f31be389771' 
  AND token = 'jDc6H2owjiNDiXlU79qUUsuVxACOcJRndq+TU3hof2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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