SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb37bf5aa4c6d727e1bd6c56bdc5a2a4d52e3bf3de5b5aba43b17b09eabb87c8' 
  AND token = 'FVk9fcKUaFsI1bCWzdmsVX/RjOnRlDqS/qLGThKCSzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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