SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '438c422f049dc40ae17aab1871d0706f57032ab3134ab46d6df9c5e50e340a65' 
  AND token = 'obSS9xvd+VqgXyQGn/HGmhKg5b9NaurSWL4Xl8i7/+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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