SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb704be7e0328ba010d4db0f5f4570a5d4436a2c2023f0d1ba6f46002bf7b22' 
  AND token = 'A7WnFLaWxeBXygRLa+exQrlvIqJ7qGNRuI+ITIjMxOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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