SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a895afb0a52fc63ef7c16bb9a0e640a8d299a81e298fb241b967ac82fffb321' 
  AND token = '/Lu04NgTE6Myh8IPYYmDTifOpd5um1CmNt9yKeLWMIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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