SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '64596fda27cd590a41399962a4afad312928d545d09f4229369bf81d05a9538b' 
  AND token = 'lZwt0Efyj/3JwBhITG7AYmhjqIGKRN53XvCy1FRTDd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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