SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b7fb265262d9bc3819c79f341baed29654b5a1e2e9cd5fce84d3645fe3d8df5' 
  AND token = 'wwWzK/FvqTht7llxD/KCRD1/VZGrRfgwF8ZjrIOJd3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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