SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'da93640035a955309d30a4353709c1e32d05725c4e2a58c7a6c5e4b8e1c5dd78' 
  AND token = 'ynVLIaZCzqrrpkVs14LssNiRoHS2XicAHzlLMAXpyMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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