SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2361e73963ed46a4f3a45911d6cb328c25f74825c828fc275b8538ad14f30471' 
  AND token = 'qjc4euQZF7Vc6QPwEeoM4/P6PIXCBzdpmRoZZoYqdHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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