SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7acf6ce8d1f2f9efc58fbdd0458ee1df4d0f4b54dbf71ae8d14938d541b283e1' 
  AND token = 'EjU3mx3ElWJOaC4hGMNbnbsYCyC/oRTYuAq/5IDFIMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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