SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '703b992f96d0d1cdb37926fca1b1c1263c94fb5fb8498b34d1749ba1c9106bb2' 
  AND token = 'zEB93xIGwwyIwPveHZXzMShWVBWR27mB/ghZ7APthPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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