SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7afa8ddf75410b675c6202c3cdecd1e86b2c39b32587321d82e04ece2329dcd' 
  AND token = 'P6HNvmbiFHm138WjO1VyRWiCTE5MFf+7byVYNMdRiws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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