SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f71c44b44b3f1729e8b3cbe3e7d2bbdeafd20b98cf34585a0738954ea41468d' 
  AND token = 'dpBEjmmOZwanUHKGqztrjpuWyX4DhXzvSWZRtn0B6EE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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