SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9666c8e93c0c1ce027c615341b6742aba7216a2df7034826870d7672fbbaa6d5' 
  AND token = 'TVMjJrBD2rpS+O2W9hJpkdzblC/jrcOJgM8rR6YwN6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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