SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40f05c5fa6ec509691f7c20247242b2a2940bce465640fa9af821001d89ed838' 
  AND token = 'WvmJMxhXfIDb+n5YJAEVMbCQn4uxTRMp6E0ehvF2CgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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