SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5afe0e87b6574a5390b53b2a33f65cff405bb63449c10fd6862eaa249751a288' 
  AND token = 'zbArCD/5MWwwWFPFM0E6enAlPLiizvVKds3wguPshrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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