SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1478cdc1fdc981575fe3dcb448ec60d14260363fb326ecccf01a106a99e5dcf9' 
  AND token = 'qOGnidX4QUCigypLRydemiDqbPPSsUZIG49VYs+vJK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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