SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdaaa57b487b9a924403a53add3e4fe5a1d083aa905b32590a805ab4b8bfb191' 
  AND token = 'TkWkHX98x0ju6T15d60o1h+MAJyrOl2rZGHfxl6IJJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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