SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffdf5679f927d9eb3a30d8095c703d62d749d64181b4966f4c5c422d3b002cb2' 
  AND token = '3tZHTdwYhivC7+aYPe0TrCvmRUxhevy7tezjgpT4hbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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