SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c35dabe26590421127e90baf7185402aa6e5d2eb7af488cbf48259d5d8bf0c55' 
  AND token = 'H3/B0NYMcilbD40mWvDoAttQfPRKH9FI0GZ3+AP4DHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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