SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4a4ffc1464c0c4f22a47c9c320cae380b9684371548aa2757cab347e1aca83' 
  AND token = 'ETmUYXSpuODI4GmVaXNvys3fGqqw9oCe9Ympoa89y+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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