SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce475982c3ba592ec7c224bbf580ab7cdf54d5b7d7a126b470c3323208da10d6' 
  AND token = 'MXIfNIAj9hmwIVL5qHkznA/m8syMUAJmDLDXWODpYlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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