SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83e1a5986e7f7fd81dc3997e95a0bfb7e9dcda4f325839b5fa8565ed18538a26' 
  AND token = 'CRPZcf5VbzfKaQn/canHSajoTl2OewJE/r+AOsWrlzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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