SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e54ed08798b963cb0e0cd35148b51870030bb41cd41672b5e9488969b0cfe4ec' 
  AND token = 'GgyJFXjaP3p2K9jqtLYtv+rTmEuSVLWMNLXS/IzVErk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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