SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc57ec72e9f4eb68dfb71d8d3d08d0069925121fc65b121656d7fbc2b641534c' 
  AND token = 'CxnfEIhD6LAkvnVIy1lpc4mk2CHseWNM55GkaIddbmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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