SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0df77adce6711ec6cde27d284d35ed2fa7f682799ffceef3fa5f00223b9f189' 
  AND token = 'fDAePBDhbT5jkUI7XFN8fkSEq4tARaPN1/VhS8kaszY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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