SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cb96c6e30009865d95a1da9a71923bade22f305edf9a5842d4205a640daf392' 
  AND token = 'yHr56DhFQOLkdqDh/gPpjxnNK34ncSp7TwTNCiwwX5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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