SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92b40fa26691405701dd38747f8d07a1a2cfcbe7f209c7cd76ebedc3c91e845a' 
  AND token = 'ktOvkrmNVKUMEcvlksly/9JFZTxcpO4xORPI3Ob+zuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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