SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34fe7a077cef59ffb8dfe02560dced6e3763077dc042a12ffcccdbc59d191086' 
  AND token = 'GNNOeDDZj9LMI4vNDgG1/A+JDakljGwJnWnMKUZlKpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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