SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b62fc5cfecf5fecdce85988ea8bcf06dab9f6ee6006771e23fd01208cc44955b' 
  AND token = 'S4zdnvBFMoqrySBBdUsc5cvbAQZrBa5ua1BGSdpyBug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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