SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f1dd800bedb6813f7b5ecbe474d306d09541dc0fcd3aea2071500afd3501dcb' 
  AND token = 'gIeXYe26pukh/YUalBcsh94q5bE1LDddkjVFyUlrNwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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