SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '08505b5d8c78ba67188610ac8664084f4fd03094c96bcab51dbbb17b1e0f8c90' 
  AND token = 'gDYVsAyGSRjB0Va4cLzl45C2z1IOLNS3vkboFnKNQPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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