SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc67c26de7c596cfb38142afd43fd198d32b1dec92c6520833930b1e67944c0' 
  AND token = 'gTbcrxUcPXbecK3UOxbRsWuhPeLw6ZUoJkwR0HrJ1UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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