SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a206d377d1845331980ed2cd0d5250a11bb5e99288c375be316b89da5a1dee' 
  AND token = 'wsLPqJU5wIamMlIFILLLaecf0qJUr9a6PXKR8qnMKro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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