SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5da36d6f45477ee45ea3265f6a4b1b1696d839ca1a4faa3699e1af0ce19618' 
  AND token = 'PtwRs+B7ogecF6GJVhKdvTVcZvXjh20vZqW3NuwG69E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}