SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4596f5b920cfd78a0aa3802358e9470f41950c7fb97d2efcb67aee6a05337c6' 
  AND token = 'Y8CQObDhKBRFj53M8zSZ/teacJZWvxiUYeHUxoanjKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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