SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c262b8dcfaf2e476df78e8d5cdf7544396713499ebf764c3eb9fa8514115a6b' 
  AND token = 'gi2Pzk5gNy6+HYlGZHJHPGeAK01r+qzEoqwRxKDPk4A=' 
  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"
    }
  }
}