SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b864b641d00c7683ddc625b5f36f62f821a624d30a8c563698ac16f862bedd3a' 
  AND token = '4QWAhywUugDqwOPjtLovZNNrVd/gR5Q+KUtvZd9EHHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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