SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0213104d207b77decc506f026e368cc8d564a7593648db727aca5452a8df1590' 
  AND token = '6wT1OFrxmdQTh/y0OWQiYJnGVtMDFsv6YwO4sCIQsw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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