SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd40aaecf4667d30745da7bb1e1ead999ead220310dbc3da556295acc088ec013' 
  AND token = 'Ms3mk7zkmzdgChiCVZihhIaLvqGFk6UfKKoZ1ZoJYmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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