SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c05a173b20fa3f89a761afbf6d66a4daba3c62ee61b371d1901bff5cab4ee577' 
  AND token = 'nK8indKFFKkIkRda240pzRRPFkmtyQ2TvT/NNCMQ1qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}