SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '707f2fc2354dcd9fd900503751e2c24f4014c1a16059564038278b05b34475af' 
  AND token = 'vpqhvF7VEKPjIuKReibLXAp9FSPCt/BI4rtueHpEtqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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