SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '37623b48e7b6d6910ab3370f78ece23f70df3c2ad493b962c55b20fd5e26c211' 
  AND token = 'UXxEvTlHvbGwPR1woszJSBV5dKaMVgenXc1zMcPOaYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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