SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '146243e69994dd395b7b2982b7d234a2ba8b502eb79d61fb7fea0325a437f781' 
  AND token = 'htilUyeIeVBu1QNrYVEaC1amO+LPOCzaxEXwPy7jqvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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