SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddb1c6ff2afb2fbf9ff7cd62d8fb11470f72706139bd79972ace1b9bcea0f43c' 
  AND token = '5OLTQ48FdzHZ418ZKdPl2NAKrYKt+DW5Kgvh+PvSz6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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