SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37906d21df6363b7d25a7ff645f6374e744035bf0ce18928c0a44c029fa9c078' 
  AND token = 'EyLLHgIHUqp+UzJUzxlqPQ+dGFU2gwToQKzCcnjLqg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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