SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da0b4bd8106ca50e15b9caac5bdb18520a5f8ce40dc447385a120d898ccf3aa' 
  AND token = 'Fvbx3mQvSehjji5rvjbK5MmiNRww1rowcDTDWTr51EM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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