SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb5a08143437d3eb9dd45da41c49b90fbcd7e98160cdb78e6a05401ed5d1827' 
  AND token = 'hSoQguXi3dspLTPZbOjA8kREGkWlX7d1BMlkKa2TKVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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