SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f384badb1a8c6e729cf06fe79ba7841f44af7c5bd05d968e7e496403165a6a0a' 
  AND token = '9TXbtTnN/YSiFUXK7S/d8PCSU/5HTW1qCkRn7or2/WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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