SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5117092e7ccb667e09f776fb8a2caf33101fc863e29852a1abf260f478e6d112' 
  AND token = 'oddrmd9RJxzIYiNh5GF/5zTN11PedASssqiW4VtMLX4=' 
  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"
    }
  }
}