SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'de5fcd241a2de58f28169b97f17069333bd78e2f3d46929487e6e3a003c318b7' 
  AND token = 'drjBv+uaVaAPYeETc30GItrzTNfZOC3J6elytlm4SmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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