SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49dd5d07de753e29c9b9ad6ff00c8f283e984209b860daff94fc580420407f2c' 
  AND token = 'rJvm544sOQvJCnBj4AiatxTI+cLlDBBMBy7HgLdyYBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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