SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32f2432626486fcc11b4b2ba2c8772f997ed32abb751aaa7c694d2e58a81b869' 
  AND token = 'c/I4hjHjpsnlXf5fDDbCODM+1mlYMkFGnu4Yq5WfLgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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