SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f045a5ffd7a8299bca6e4857cba0d232ed44c04443885dde3d6c25d3e6f3479c' 
  AND token = 'l6tVgRL5uGZTawOakA7xBvWc5KcMgvSw8IpXk64c2nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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