SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ea9fb81986e0a7fbe94896170f6d462a0a45ef928b464ff1ba34c694b290e64' 
  AND token = 'GTFJjI1LQIrq/1LBjzz2UBH7OruvbvckMCPG5JBu248=' 
  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"
    }
  }
}