SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c060402d13228f6ed1d9dc2ae8c41cfc3a02a19c4b8d20f9a4e6a32c1368b50' 
  AND token = '5hHIRpdMMARfZNYIZiOy2yE9LH8nyZdR8q692ibZ2GU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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