SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28b6c61317e581578bbe552d049fbb16d6188f4a429cb54b19d2c8b260299043' 
  AND token = 'FeaFzNptaMPvKPRXfyVLa8NbMx6yR1e/rhVs6oQgNpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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