SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01dd6bae11fc249bdf0e30644a02ec03d8902dfbf90e328a20ce0b707cea4346' 
  AND token = 'dsQnEOpJmf9a3UG6tpBb/O3GU3tcXQ9DOP7Q47oN5G0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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