SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b87b8541817d7f88b0c97f48d7316121e5fe3885a01ed9bef38caf14293ad08' 
  AND token = 'PbV/DM53orMpVlQkCnk2NNSU7b+N5ZRem7sbEywGnNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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