SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e6eea063a603a2fb2f4ff117991b658d7cc6064a4122de2f3f159370438ce2' 
  AND token = 'JLUZAqlllUP7LoTbzV8os4ghufyp9kqQ1vzNrVUW+fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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