SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5ab84b434f5142af0e29631e4e27583099054b9d716e7c5c2a89f6f360243ef' 
  AND token = 'MWy+jHITBJtJY1RVcYgc4vUE1Q0u2Pj/zg5TCCWRhDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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