SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be7529e5d0cfd56ff189a2a19de8bdbf2e3e5feb660b1734cba6039110c96317' 
  AND token = 'KpzYdcc2nxHSyYGdQAabWL6652A4TIdzPGMeazgb6tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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