SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9dacaa9567aad7e581dd69f66f586e106d3f409329b7e499573f8bf8bb39e377' 
  AND token = 'QsfUqECH4KODnzqW4LKrVBoeutUb7XZi/nhrX3I9XYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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