SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fb4b5fe8f9c0378665832d49b8d9fd0ff64fb51c8c8b99af8b55506f502e233' 
  AND token = 'qd+BMsDjvf2zJgORG9cLQYlo/A+RuD2D98U9KfZdXeE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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