SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb564fa469a7394bc69e3d7d21b50b851db09de1ee6e795db09260934010737d' 
  AND token = 'ZSzl/Nh74p0FzuyWTJJlb0m2b3WSEo7yCf7EUpnK+FM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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