SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e72ab8e4c3b5b3e016910483e552b9fa0d0f9eed82fc461c1c588604435c10b' 
  AND token = 'fnWyYEf7+GRPBjPtdJF1nQXITUSKQMhvUX8kZYFz0fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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