SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f554adf310262a1ee8860a0837c51725332591cc14cda3b0ad94a17eaf10f9ba' 
  AND token = 'RVnXpp2fNekg1ip8FkQVRek28DWQwUZBsbwa3jKekcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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