SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c2c41f16453654dcf0b9ef79fe8c80824193c17aa0c31fa747a37e1b79ac5d4' 
  AND token = 'XMpqjY+SvTqy2VJIOd6zm5blabVMDT+Y/hUr0LUP6yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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