SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10da7d99657fc65978db6d37b07909455d7e1c16726b74d72d30ca53ce0ea1f0' 
  AND token = 'ZegSgtlXD0p2gqjZftFwrccs1ZD8SKST8aNvjOebpH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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