SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a411276f897ff266c75da4748b6b08db2712aadec51d8934b1ce900635b20e68' 
  AND token = 'VUcQjpH07s1wAeHKpLNSE/U/FN2V0DwjhdLdHTVTZvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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