SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37c47ceafe04990be564ba9fb9dde25b17d4959a97063dc1fc02b85e98ffdb72' 
  AND token = 'of4GrTnXjV0K7Tuj/nCbmRPXS2PhTZtWRvBvEIp5PSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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