SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b05b771f5f3ca6170a8e2578b1f3dd17d4111fd2ffda171026d6b653c0a438a' 
  AND token = 'smNEs9oQhfAeYKrNPuRNNgh8bPqhyVITajFxezyznkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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