SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e8b85f67ec67344b08d6d955084bddbaa93a000d0962cde5e5de09314bdb04a' 
  AND token = 'vtkK47MfEz6pwNYlnLGHUh1UuFeJTiqBIVZ8nKWZvnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00105

JSON explain

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