SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cf19f36ae1042f8aecd81969c0d9efc81fa5c4e1e1231906cfb96c1ef8475ba' 
  AND token = '23qeH1nf9Ven6h8s+3c8KNSGAALZxPjn6eMpzI1I3ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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