SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '752f58109dcf1d7330dfb5bb70f041f6c2b4a88d39573b526059f8e8e72799a3' 
  AND token = 'wFG+CX+VfNZX/QeLor4TdrMqI5E0O5iBKOk4OBteAqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}