SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5899ca6258a262c27a8a72c48a7efb0701511aaf907f88458b00972cfa8936b3' 
  AND token = '/PdXvXIEgkC8axDNtGsQOgP9vqRm2zkrLUF5rgvEsk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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