SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '996a2db60b302b82b146927052cc15b7c1f5dd142a247af39fc345547f69a6b0' 
  AND token = 'dsLqdSefnfJq9Rb4/OiJuTIm1WRYGGjxy9hFMEOiHCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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