SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5ad6f494fd4e30ec17cbaff88d311cc565b8f468249b24d4c147972c8bd610d' 
  AND token = 'ypH+2SyVRwYnOl9hq6eayVz+syI+W38V3bz1ttJUGek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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