SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5553396387099826ab2b0f43cacf509552afdacae1393592cd56980e13d88c9' 
  AND token = 'pz4qWDbLbZPZ2gq5ZHtQazqS/hyslQuf0tXgt7uP/X4=' 
  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"
    }
  }
}