SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c05570ac7ca3ac3a3dcdbe84a93b6646d44c776ee1169ec5ad1df3dfe5bd205a' 
  AND token = 'mVUvsDXoLugB9+KGe9a9GKmNF2gwAkCOzSSpJWd4aYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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