SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d3b05a8684fb0c5f5a25e00a18c20c8b60185cb9d540213d1cb3bf9f93cdfd3' 
  AND token = 'C5gIT9559QJ3Sg1sK64fdD3i+iltY7BIYC+jUuuWfIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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