SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da38cd215c4ea839d50046c05f90f8673bfb08eaf05b7931c145cd4ac13bd696' 
  AND token = '1gKZ9E9jc9e6k2I9jUEMJx/ZNuAGclnZMaFgTYfk80g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}