SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b554b10a8b58aff6ebc60363308df0a9e157aac56be5162aea5f9105f00f6a05' 
  AND token = 'bZHER6rgAcuAqV3LjzZ/Kasi25RHwly/ZGVTDBXLqQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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