SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae056e538f92b49d256e9951bccc4c8e9a171ee1bfebedd6750730b950da404d' 
  AND token = '4NcEK8UFhfuYYjQMMnCJPHbtmWzTKUn48P8QtnGISqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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