SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ef35f3afb5ca2c8d57254debca3fd9da798fd355c4b04eb44dcdd8f89e0fa64' 
  AND token = 'tm+PtKq3q0NJxrZvlY5QvsmXhguox7uZtPK7pXp2X6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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