SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd59280fdd7cdd76a5c5f427600c7a70e8b822e795b06bcbb78ef1f1ec3a5cf1c' 
  AND token = '4Yr/jZhJK8ZfzGGGHt3Zq4yRWIPc9nU5quzNgrJXDwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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