SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b9ed98c395c373de8fdca108c27159d0e495a9f8145f956be1d2e10166f7c6c' 
  AND token = 'QG3tmKBZ+KuxhH5/NOLnoXupQ5HdkECs/1t//xHHWtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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