SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6c10e94be3372a4b568783a9087de714b89b01a74df208b782a88aee1d670ba' 
  AND token = 'v0OqP1FysHoTp8TaXVIRaZOtAFGQnaRFJuJhJjx/sAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}