SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f76009a35147fb9e9a3a0701c735d4f5f271f6a27850dbdc963818bd283d21a4' 
  AND token = 'wLrqkaGYumaitmou3BJcYGwnxcT4RD2fAi3qOQwGWjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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